The problem was, Apple had only applied for a patent on a text-while-you-walk system that would overlay message conversations on your phone camera’s view of your surroundings. Oops.

So I tweeted something, um, transparently wrong. Now what? I’ve attended more than one panel discussion on this, and the answers usually get stuck on one of two conflicting imperatives: Don’t let the error go unfixed, but don’t look like you’re hiding the mistake either.

Since you can’t edit the incorrect tweet or even flag it as wrong in the way you could amend a flawed story or blog post, letting it stand risks perpetuating the mistake. But if you delete it, then the evidence of your error vanishes.

What I decided to do was to delete the tweet, follow up by saying what I’d gotten wrong, and then redo the original tweet with a reasonably obvious hashtag, #corrected, to indicate that it was a “CX” for an earlier version:

A week or two ago, as I was reading the corrections box on page A2 of the Post, I thought to myself that it had been a while since I’d had to run a “cx” on my own work. I credited having a saner workload… and then wondered if I was due for an error anyway.

Sonic’s CEO Dane Jasper spotted the mistake within a few hours of the story’s appearance and notified me in a Twitter message. I e-mailed my editor, who had it fixed minutes later… and then I could get on with my “how could you?!” follow-up. (Figuring out how an obvious error wormed its way into a story is more constructive than walking around and cursing at yourself.)

The Versions feature of Apple’s OS X Lion, as seen at right, revealed that I didn’t add the price of the service to a draft of the story until Feb. 13–weeks after I’d started my reporting. Then I typed in the wrong number and kept using it from then on.

The Evernote file with my notes from interviewing Jasper and some of his customers had never included that price. My e-mail showed that I did mention the right number, rounded up to $70, in my pitches to Discovery News (which should soon post my take on what a connection that fast feels like) and then Ars–but had subsequently written “$79.99” to one source on Jan. 25 and to another on Feb. 11.

It appears that this number lodged itself firmly in my brain and never got out.

So that’s this week’s lessons re-learned: Put the important numbers in your notes at the start instead of leaving them in your head, and link to your sources, so readers don’t have to take your word for things. Or just don’t be a flake.

(I’ve yet to see any readers call me out on this. But I’m irked anyway, which is why I just devoted almost 500 words to unpacking my mistake.)